When Does "He" Officially Become "She" (Or Vice Versa)?

When is it appropriate to change the pronoun you use to refer to a transgender person from his or her birth gender to her or his new gender identity?
As soon as the person identifies as transgender29
Not sure27
Never20
After gender reassignment surgery12
Once the person exhibits the public appearance of a given gender 8
Once the person begins any medical treatment, for example hormone therapy4
Sources: d25d2506sfb94s.clou…